Wednesday, May 15, 2013

De Novo Mutations, Autism, and Congenital Heart Disorder

De novo mutations are new mutations that occur often in response to an environmental insult.

People with autism have more de novo mutations than their parents and relatives. A study, described below, examined how de novo mutations to fathers' germ line cells (reproductive cells) is correlated with autism in their children:

Hathaway, Bill (2012, April 4). Genetic mutations at conception linked to many cases of autism,

[Excerpted] About 15 percent of autism cases in families with a single autistic child are associated with spontaneous mutations that occur in sex cells, Yale University researchers report in the April 4 issue of the journal Nature.

The findings are the result of DNA sequencing of every gene in 238 families, each with only one autistic child — the most sophisticated analysis yet of the genetic links to autism. The study identified hundreds of such de novo or spontaneous sequence variations, and as more are discovered, medical science may find new ways to intervene in the disabling disorder, the authors say.

The Yale team, in cooperation with researchers at Carnegie Mellon University, the University of Pittsburgh and UCLA, also linked variations in three specific genes to a markedly increased risk for autism.

...The new Yale study also showed that these de novo mutations were more frequent in children born to older fathers, offering at least a partial explanation for the increased risk for autism in children of older parents....[end]

Majia here: De Novo mutations have also been linked to congenital heart disease:

Christian Nordqvist 10% Of Congenital Heart Disease Not Inherited From Parents

[Excerpted] Ten percent of babies born with congenital heart disease have genetic mutations that occurred while they were in the womb, i.e. they did not inherited the genetic mutations from their parents, researchers reported in the May 12th issue of the journal Nature.

...According to new research, approximately 10% of congenital heart defects are caused by genetic abnormalities which are not present in the infant's parents.

..."The mutations in patients with congenital heart disease were found much more frequently in genes that are highly expressed in the developing heart."

...They found that approximately 10% of severe cases of congenital heart diseases were caused by de novo mutations....

...Lifton explained that severe congenital heart defects were caused by mutations in many hundreds of different genes - they were concentrated in a pathway that regulates key developmental genes. These genes affect a system of chemical tags that alters gene expression - the epigenome.... [end]

Majia here: De novo mutations are incurred through some genetic injury. But what causes genetic injury?

Many heavy metals and radioisotopes are likely culprits given how widely dispersed these radiotoxic elements are in our food supply, air, and water.

Today I read that arsenic levels are particularly high in American rice, even in organic rice, because the fertilizer used on organic rice is from cows that were fed arsenic to combat bacterial infection.

Arsenic is highly toxic and its probably in all organic food products that use animal-based fertilizer unless said animals were fed organic diets free of arsenic.

I read recently that chicken contains high arsenic content because chickens are fed arsenic also. See discussion here in The New York Times.

Yum, yum. Arsenic in our rice, beef, and chicken.
And lead can be found in our baby food. 
An ongoing lawsuit in California is trying to force baby-food producers to post warning labels about lead in their products. Gerber fought the suit saying that their manufacturing is not responsible for the lead found in their baby food. See here for background

That may be true, but one wonders how lead is ending up in pears and peaches, among other foods. Has the environment become that contaminated that now all our food contains 'un-natural' levels of lead and arsenic?

Meanwhile, the "EPA Fails to Tighten Lead-Poisoning Hazard Standards" USA Today (March 11, 2013) p. 3B despite recommendations to do so from "the agency's own scientific advisers."

De novo mutations for everyone!

1 comment:

  1. "The third finding is that the silicofluorides, as obtained from the scrubbers of the phosphate industry, contain a wide variety of impurities present in the process water – particularly arsenic and possibly radionuclides. While these impurities occur at low concentrations, especially after dilution into the water, their purposeful addition to water supplies directly violates EPA public health goals. For instance, the EPA’s Maximum Contaminant Level Goal for arsenic, a known human carcinogen, is 0 parts per billion. However, according to the National Sanitation Foundation, the addition of silicofluorides to the water supply will add, on average, about 0.1 to 0.43 ppb, and as much as 1.6 ppb, arsenic to the water."


Note: Only a member of this blog may post a comment.